Boom structure

ABSTRACT

A portable boom structure for moving a load includes an elongated boom having one end thereof pivotally mounted on a mobile frame and positioned intermediate the ends of the frame and a boom support member having one end thereof spaced from the one end of the boom and pivotally mounted on the frame and the other end adapted to be in supporting engagement with the boom. A suitable cable operatively engages the other end of the boom support member to selectively raise and lower the boom and a suitable cable engages the other end of the boom to selectively raise and lower the load. Spaced legs each have an upper end thereof pivotally mounted on the boom support member and the other end of each of the legs is adapted to be in supporting engagement with the ground surface. The boom structure includes a load control device adapted to control swinging movement of the load relative to the frame.

United States Patent [191 Bronfman 1 Oct. 14, 1975 BOOM STRUCTUREPrimary ExaminerRobert J. Spar Assistant ExaminerLawrence J. Oresk 76 It: D 18 f ,4000E.Rd 1 Y 1 men or :2; gg gg City Attorney, Agent, orFirm-Fishburn, Gold & Litman [22]" Filed: Feb. 28, 1974 [57] ABS CT 1 ppNO 446 639 A portable boom structure for moving a load includes 52 [51]Int. Cl. B66C 23/00 [58] Field of Search 104/263; 212/8 R, 8 B, 212/9,145; 214/130, 75 H; 9/39; 240/67; 254/127, 128, 185 R [56] ReferencesCited UNITED STATES PATENTS 1,041,266 10/1912 Gardner 212/58 R 2,()6(),867 1 1/1936 Hollerbach 214/93 2,277,235 3/1942 Kidder 212/422,651,498 9/1953 Straub... /127 2,786,582 3/1957 Foster 212/ R 2,807,3749/1957 McLean 212/8 R 3,3()( l,l89 1/1967 Blount 254/185 R 3,523,6158/1970 Anderson et a1 212/185 R 4 23 42 9 I07 I 90 44 I 43 US. Cl. 212/8R; 212/8 B; 212/145 an elongated boom having one end thereof pivotallymounted on a mobile frame and positioned intermediate the ends of theframe and a boom support member having one end thereof spaced from theone end of the boom and pivotally mounted on the frame and the other endadapted to be in supporting engagement with the boom. A suitable cableoperatively engages the other end of the boom support member toselectively raise and lower the boom and a suitable cable engages theother end of the boom to selectively raise and lower the load. Spacedlegs each have an upper end thereof pivotally mounted on the boomsupport member and the other end of each of the legs is adapted to be insupporting engagement with the ground surface. The boom structureincludes a load control device adapted to control swinging movement ofthe load relative to the frame.

8 Claims, 7 Drawing Figures US. Patent I Oct. 14, 1975 Sheet 1 of43,912,088

m ON US. Patent Oct. 14, 1975 Sheet 2 of 4 3,912,088

US. Patent Oct. 14, 1975 Sheet 3 of4 3,912,088

U.S., Patent Oct. 14, 1975 Sheet 4 of4 3,912,088

BOOM STRUCTURE The present invention relates to boom structures and moreparticularly to a boom structure having a boom support member adapted toraise and lower a boom and having spaced legs depending therefrom andeach adapted to be in supporting engagement with aground surface.

The principal objects of the'present invention are: to provide for aportable boom structure for moving a load wherein the boom structure is.easily maneuverable to position the load at a selected location; to provide such a boom structure which may be transported or shipped in aknocked down or disassembled condition and assembled at the site of use;to provide such a boom structure which is simple to assemble; to providesuch a boom structure which is adapted to be manually operated and,therefore, conserve energy; to provide such a boom structure having anovel structure adapted to support and to raise and lower a boom withstability in all directions; to provide such a boom structure having aload control device adapted to control swinging movement of a loadrelative to the boom structure; to provide such a boom structure havingspaced pivotally mounted legs depending from the boom support member andadapted to be in supporting engagement with a ground surface; to providesuch a boom support structure wherein the legs are adjustable in lengthas required by the position of the boom and the height of the groundsurface; to provide such a boom structure adapted to lower a load intoan excavation and adapted to raise a load out of an excavation; toprovide; such a boom structure having a boom and boom support membereach movable through a wide arc whereby the boom structure is versatilein use; and to provide such a boom structure which is stable in use,economical to manufacture, durable in construction, and particularlywell adapted for the proposed use.

Other objects and advantages of this invention will become apparent fromthe following description, taken in connection with the accompanyingdrawings, wherein are set forth, by way of illustration and example,certain embodiments of this invention.

The drawings constitute a part of this specification and includeexemplary embodiments of the present invention and illustrate variousobjects and features of the boom structure.

FIG. 1 is a side elevational view of a portable boom structure embodyingfeatures of the present invention.

FIG. 2 is an end elevational view of one end of the boom structure.

FIG. 3 is a plan view of the boomstructure.

FIG. 4 is an enlarged top plan view of a load control device mounted onthe boom structure.

FIG. 5 is a side elevational view of a lower portion of an other form ofthe portable boom structure.

FIG. 6 is a side elevational view of an upper portion of the other formof the portable boom structure.

FIG. 7 is a top plan view of upper portion of the other form of theportable structure.

Referring more in detail to the drawings:

As required, detailed embodiments of the present invention are disclosedherein, however, it is to be understood that the disclosed embodimentsare merely exemplary of the invention which may be embodied in manyvarious forms. Therefore, specific structuraland functional detailsdisclosed herein are not to be interpreted as limiting but merely as abasis for the claims and as a representative basis for teaching oneskilled in the art to variously employ the present invention invirtually any appropriately detailed structure.

In the disclosed embodiment of the present invention, the referencenumeral 1 generally designates a portable boom structure for moving aload 2. The portable boom structure 1 includes a boom 3 having one end 4pivotally mounted on a frame 5 and positioned intermediate opposite ends6 and 7 thereof. The boom 3 is engaged by a boom support member 8 havingone end 9 spaced from the one end 4 of the boom 3. The one end 9 of theboom support member 8 is pivotally mounted on the frame 5. The other end10 of the boom support member 8 is adapted to be in supportingengagement with the boom 3. A cable 11 is operatively engaged with theother end 10 of the boom support member 8 to selectively raise and lowerthe boom 3. A cable 12 is operatively engaged with the other end 15 ofthe boom 3 to selectively raise and lower the load 2. Spaced legs 16 and17 depend from the boom support member 8 and have upper ends 18 and 19respectively pivotally mounted on the boom support member 8. The legs 16and 17 have the other ends 20 and 21 respectively thereof adapted to bein supporting engagement with the ground surface 22. The boom structureincludes a load control device 23 adapted to control swinging movementof the load 2 relative to the frame 5 during raising and lowering of theload 2.

The frame 5 may be any suitable structure adapted to support the load 2moved by the boom 3 and the frame 5 may be stationary or movable asdesired. In the illustrative structure, the frame 5 has one of the endsthereof, for example end 6, adapted to be removably connected to amobile vehicle, such as a truck, tractor or the like. The end 6 has afront or forward end portion having a suitable ring 24 adapted toreceive and be removably retained on a suitable pintle hook 25 mountedon the mobile vehicle. The front or forward end 6 of the frame 5 hasdiverging side members 26 and 27 extending rearwardly and outwardly fromthe ring 24 and the side members 26 and 27 are suitably secured to amain portion of the frame 5, as by welding.

The main portion of the frame 5 includes a front member 28 having thediverging side members 26 and 27 of the forward end 6 secured theretoadjacennt respective opposite ends of the front member 28.Longitudinally extending and laterally spaced pairs of side members 29and 30 each have the front end thereof suitably secured to the frontmember 28, as by welding, and the rear ends of the pairs of side members29 and 30 are suitably secured to a rear member 31 to thereby provide asubstantially rigid frame. The frame 5 may also have one or more bracingor reinforcing members as desired to strengthen the frame or providesupport for equipment or accessories carried on the boom structure 1.

A support member 32 is mounted on the front end 6 of the frame 5 and isadapted to support same in spaced relation with the ground surface 22when the frame 5 is not connected to the mobile vehicle. In theillustrated structure, the support member 32 includes an internallythreaded tubular standard 33 having a portion thereof depending belowthe front end 6 of the frame 5. A threaded pintle 34 is received withinthe tubular standard 33 and is movable longitudinally thereof. A castertype wheel 35 is mounted on the lower end of the pintle 34 and isadapted to engage the ground surface 22 thereby supporting the front orforward end 6 of the frame 5.

The illustrated frame includes two pairs of laterally spaced groundengaging wheels 36 and 37 mounted adjacent the other or rear end 7 ofthe frame for supporting the frame 5 for movement along the groundsurface 22 by the mobile vehicle (not shown). An axle 38 is secured toeach of the pairs of side members 29 and 30 and is positioned adjacentthe rear member 31 and substantially parallel therewith. Each axle 38 isadapted to rotatably support the respective pair of wheels 36 and 37adjacent respective opposite ends thereof.

Suitable fenders 39 and 40 are secured to the frame 5 and positionedabove the pairs of wheels 36 and 37 respectively in a conventionalmanner and for a conventional purpose.

It is particularly desirable to balance the load 2 being lifted by theboom 3 particularly when the load 2 is positioned well beyond the rearend member 31 of the frame 5, therefore, suitable ballast tanks 41 whichare adapted to contain water, sand, rock, concrete or other ballast aremounted on the frame 5 and positioned adjacent the forward end 6thereof.

The boom 3 is an elongated member having the one end 4 thereof pivotallymounted on the frame 5. The one end 4 of the boom 3 is positionedintermediate the ends of the frame 5 and in the illustrated structure,and end 4 is positioned adjacent the front member 28. The boom 3 may beany desired structural member, such as an I-beam, H-beam, truss, or thelike.

The illustrated boom 3 includes a tubular member forming a portion of atruss which provides a substantially rigid boom. The illustrated trussincludes a top member 42 spaced from the substantially parallel with atubular bottom member 43. The top member 42 includes opposite endmembers 44 and 45 each extending from a respective end of the centerportion of the top member 42 to the respective opposite end of thetubular bottom member 43. A plurality of spaced web members 46 extendbetween and have respective opposite ends secured to the top member 42and to the tubular bottom member 43.

The pivotal mounting of the one end 4 of the boom 3 on the frame 5includes spaced end sleeves or axle supports 47 and 48 mounted adjacentthe pairs of side members 29 and 30 respectively of the main portion ofthe frame 5. The axle supports 47 and 48 are suitably secured to theframe 5 and extend upwardly above the front member 28 of the frame 5.The end sleeves 47 and,48 are adapted to rotatably receive an axlemember 49 which has respective opposite ends thereof freely rotatable inthe axle supports 47 and 48.

Axle retainers 50 and 51 are sleeved on the axle member 49 and securedin position adjacent the axle supports 47 and 48 respectively, as bysuitable set screws or the like, to thereby resist lateral movement ofthe axle member 49. The one end 4 of the boom 3 has a tubular end member52 extending laterally or transversely to the longitudinal axis of theboom 3 and sleeved on the axle member 49 whereby the boom 3 is freelyrotatable about the axle member 49 and the axle member 49 is freelyrotatable in the axle supports 47 and 48. Boom retainers 53 and 54 aresleeved on the axle member 49 and secured thereto adjacent opposite endsof the tubular end member 52, as by suitable set screws or the like, tothereby resist lateral movement of the one end 4 of the boom 3 along theaxle member 49.

The other or upper end of the boom 3 is adapted to be operativelyengaged by the cable 12 which is operative to raise and lower the load2. In the illustrated structure, a pulley or sheave 55 is rotatablymounted on the upper end of the boom 3, as by a suitable removable block56 having a sleeve portion 57 which is suitably removably secured to theupper end of the boom 3,'as by a plurality of spaced bolts. The block 56has an end member 59 spaced from the end of the boom 3 and adapted toclose the block 56. An axle 60 has the pulley orsheave 55 rotatablymounted thereon and the axle 60 extends through the sleeve portion 57and is suitably secured thereto, as by nuts.

The boom support member 8 has the one end 9 thereof pivotally mounted onthe frame 5 and the other end 10 of the boom support member 8 is adaptedto be insupporting engagement with the boom 3. The one end 9 of the boomsupport member 8 is spaced from the one end 4 of the boom 3. Theillustrated boom support member 8 has spaced side frames 61 and 62 eachhaving a lower end thereof pivotally mounted on the frame 5 and the boomsupport member 8 has at least one connecting member 63 extending betweenthe upper ends of the side frames 61 and 62. A wheel 64 is rotatablymounted between the upper ends of the side frames 61 and 62 and has aperipheral rim surface 65adapted to be in supporting engagement with thetubular bottom member 43 of the boom 3.

In the illustrated structure, end sleeves or axle supports 66 and 67 arepositioned adjacent the pairs of side members 29 and 30 respectively ofthe main portion of the frame 5 and the end sleeves or axle supports 66and 67 extend above the rear end member 31. An axle member 68 hasopposite ends thereof received in the end sleeves or axle supports 66and 67 and the axle member 68 is freely rotatable therein. Tubular endmembers 69 and 70 are mounted on the lower ends of the side frames 61and 62 respectively and the tubular end members 69 and 70 extendtransversely to the longitudinal axis of the boom 3 and are freelyrotatable on the axle member 68.

Retainers 71 and 72 are positioned on the axle member 68 adjacent andbetween the tubular end member 69 and 70 of the side frames 61 and 62.The retainers 71 and 72 are suitably secured to the axle member 68, asby suitable set screws to thereby position respective end members 69 and70 adjacent the respective end sleeves or axle members 66 and 67. Axleretainers 73 and 74 are suitably secured to opposite ends of the axlemember 68 and positioned outwardly of the end sleeves or axle supports66 and 67 to thereby maintain the axle member 68 within the end sleevesor axle supports 66 and 67.

The side frames 61 and 62 are positioned on opposite sides of the boom 3and each includes side members 75 and 76 having their lower ends securedto a respective one of the tubular end members 69 and 70 and divergetherefrom. An end member 77 extends between the other ends of the sidemembers 75 and 76 to complete the respective side frame. An axle 78extends between the side frames 61 and 62 and has opposite ends thereofsuitably secured to one of the side members of each of the frames 61 and62. The axle 78 is positioned below the boom 3 and has the wheel 64rotatably mounted thereon. A connecting member 63 is positioned abovethe boom 3 and is suitably secured to the other side of the frames 61and 62. I

The end members 77 have suitable means thereon for connecting the cable11 thereto for raising and lowering the boom support member 8 relativeto the frame 5, as later described.

The boom structure 1 includes spaced legs 16 and 17 depending from theboom support member 8 and having the upper ends 18 and 19 respectivelythereof pivotally mounted on the boom support member 8. The legs 16 and17 have the other or lower ends 20 and 21 respectively thereof adaptedto be in supporting engagement with'the ground surface 22. The legs 16and 17 are each adjustable in length to thereby support the boom 3 at aselected spacing above the ground surface 22.

In the illustrated structure, projections 80 and 81 extend outwardlyfrom the side frames 61 and 62 respectively to pivotally receive theupper ends of the legs 16 and 17 respectively. The side frames 61 and 62are suitably reinforced, as by a reinforcing member 82 extending betweenthe respective end member 77 and the side member having the respectiveprojection thereon.

The legs 16 and 17 are each illustrated as being formed of telescopingmembers each having a plurality of longitudinally spaced aperturesadapted to receive suitable pins or bolts 84 to hold the telescopingportions in a selected relation. A lower end of the lower member orportion of the telescoping legs 16 and 17 have feet 85 and 86respectively adapted to engage the ground surface 22 thereby supportingthe boom support member 8 and the boom 3 thereon.

The upper ends of the legs 16 and 17 are freely pivotable about theprojections 80 and 81, therefore, the frame 5 has suitable means thereonand connected to the legs 16 and 17 for retaining same at a selectedspacing from the frame 5. In'the illustrated structure, a suitableflexible member, such as a chain, cable or the like, passes throughsuitable eyes or guides 87 and 88 on the legs 16 and 17 respectively andhas opposite ends thereof removably secured to the rear end of the frame5 to hold the legs 16 and 17 in a selected position.

The cables 11 and 12 are extended and retracted by suitable winchespreferably mounted on the frame5. ln the illustrated structure, aplatform 89 extends upwardly from the forward or front end 6 of theframe 5 and has a first winch 90 operative to dispense and retract thecable 11 which operatively engages the other end 10 of the boomsupport'member 8. The cable 11 may have a suitable hook on the endthereof which is engaged with the connecting member 63 or a suitablepulley or block may be pivotally supported on the connecting member 63with the cable 11 extending therearound with the end of the cable 11being secured to the platform 89.

A second winch 91 is mounted on the platform 89 and spaced from thefirst winch 90 and isoperative to extend and retract the cable 12 in anysuitable conventional manner with the cable 12 extending over the pulleyor sheave 55 on the upper end of the boom 3.

The boom support structure 1 includes means mounted on the frame 5 andoperatively engaging the means for raising and lowering the load 2 forcontrolling movement of the load 2 relative to the frame 5. In theillustrated structure, a support or housing 95 is mounted on the frame 5and has opposed upstanding ends portions 96 and 97. An elongated shaft98 extends between and is rotatably mounted on the end portions 96 and97. The shaft 98 has suitable means thereon, such as a handle 99, forrotating the shaft 98. A first sheave 100 is mounted on the shaft 98 andsuitably secured thereto, as by being keyed to the shaft, and the firstsheave 100 is thereby rotatable with the shaft 98. A second sheave 101is mounted on a sleeve I 101' which is rotatably mounted on the shaft98. The second sheave 101 is spaced from the first sheave 100. Thesecond sheave 101 and the sleeve 101 are movable longitudinally of theshaft 98. The first and second sheaves 100 and 101 have facing gears 102and 103 respectively engaged by a suitable miter or bevel gear 104, aslater described, whereby rotation of the first sheave 100 in onedirection effects rotation of the second sheave 101 in the oppositedirection.

. -A cable 105 is mounted on the first sheave 100 and has suitable meansthereon, such as a hook 106, adapted to be connected to a respectiveportion of the load 2. A cable 107 is mounted on the second sheave 101and has suitable means thereon, such as a hook 108, adapted to beattached to a respective portion of the load 2 whereby one of the cables105 and 107 is selectively dispensed and the other cable is retracted tothereby control movement of the load 2 upon rotation of the shaft 98, asby the handle 99. The handle 99 may also be held in position to preventturning of the load 2.

The miter or bevel gear 104 is connected to a handle or lever 109 whichis pivotally mounted on the housing 95, as by a shaft extending throoughan aperture in the housing 95, whereby the gear 104 may be selectivelymoved into and out of operative engagement with the gears 102 and 103 onthe sheaves 100 and 101.

FIGS. 5 to 7 inclusive illustrate an other form of the portable boomstructure wherein a boom extension 110 is mounted on the upper end ofthe boom 3 to thereby position the load 2 at a greater distance from therear of the frame 5. The boom extension 110 is mounted on the upper endof the boom 3 by removing the block 56 from the boom 3 and securing theblock 56 on the upper end of the boom extension 110. The boom extensionhas a mating lower end having sleeve portion 111 substantially similarto the sleeve portion ,57 which is attached to the lower tubular member43, as by suitable bolts. I

The boom extension 110 is illustrated as having a lower tubular member113 defining the bottom portion of a truss having a top member 114spaced from and substantially parallel with the lower tubular member 113and having end member 115 and 116 extending from respective ends of thetop member 114 and secured to the lower tubular member 113. Suitable webmembers 117 extend between the lower tubular member 113 and the topmember 114 to thereby provide a substantially rigid member.

Suitable bracing collars 118 and 119 are removably secured to the lowertubular member 43 of the boom 3 and the lower tubular member 113 of theboom extension 110 respectfully. The bracing collars 118 and 119 extendlaterally from the lower tubular member 43 and the lower tubular member113 respectively and have side tie members 120 and 121 extending betweenand suitably secured to the collars 118 and 119, as by nuts mounted onthreaded ends of the tie members 120 and 121.

Also illustrated in FIGS. to 7 inclusive is a frame extension 122 havingside members 123 and 124 extending rearwardly from the rear member 31 ofthe main portion of the frame 5 and secured to the legs 16 and 17respectively and a bracing or tie member 125 extends between the legs 16and 17 to thereby provide a substantially rigid structure for supportingthe boom support member 8. The side members 123 and 124 may betelescoping to permit the legs 16 and 17 to be positioned at a selectedlocation relative to the frame 5, as determined by the position of theboom support member 8. Suitable wheels 126 are mounted on the lower endsof the legs 16 and 17 whereby the modified boom structure may bemaneuvered with the legs 16 and 17 in position supporting the boomsupport member 8 and the boom 3.

The boom structure having the boom extension 110 and the frame extension122 is used in substantially the same manner as the boom structure 1except that the boom extension 110 permits placing loads in excavationafter the boom structure is moved adjacent said excavation.

The boom structure illustrated in FIGS. 1 to 4 inclusive and the boomstructure illustrated in FIGS. 5 to 7 inclusive may be disconnected fromthe respective prime mover and operated independently thereof. Therespective prime mover may then be used for any other desired use.

It is to be understood that while I have illustrated and describedcertain forms of my invention, it is not to be limited to these specificforms or arrangement of parts herein described and shown.

What I claim and desire to secure by letters patent is:

1. A boom structure comprising:

a. an elongated generally horizontal frame having opposite sides andopposite ends, said frame having means adjacent the opposite endsthereof for supporting said frame relative to a ground surface;

b. an elongated boom having an upper surface and a lower surface and oneend thereof pivotally mounted on said frame, said one end of said boombeing positioned intermediate the ends of said frame;

c. an elongated boom support structure having one end thereof pivotallymounted on said frame adjacent one end thereof and the other end adaptedto be in supporting engagement with the lower surface of said boom, saidone end of said boom support structure being spaced from said one end ofsaid boom, said boom support-structure having laterally spaced sideframes each positioned on respective opposite sides of said boom andhaving a lower end thereof pivotally mounted on the one end of saidframe adjacent a respective one of the opposite sides thereof, said boomsupport structure having a wheel rotatably mounted between upper ends ofsaid frames and having a peripheral rim surface in supporting engagementwith the lower surface of said boom;

d. an elongated flexible member operatively engaging the other end ofsaid boom support structure and means operatively connected to saidflexible member for moving said boom support structure to therebyselectively raise and lower said boom; and

e. a second elongated flexible member extending over the other end ofsaid boom and means operatively connected to said second flexible memberfor selectively raising and lowering a load,

f. said boom support member further having elongated legs each havingand end thereof pivotally mounted on the other end of said boom supportmember and the other end thereof adapted to be in supporting engagementwith the ground surface at a location spaced from the one end of saidframe.

2. A boom structure as set forth in claim 1 wherein:

a. one end of said frame is adapted to be removably connected to amobile vehicle;

b. said frame has laterally spaced ground engaging wheels mountedadjacent the other end thereof for supporting said frame for movementalong the ground surface by the mobile vehicle; and

.c. said legs are each adjustable in length to thereby support said boomat a selected spacing above the ground surface and to accomodate unevenground levels.

3. A boom structure as set forth in claim 2 wherein:

a. said boom support member has spaced side members each having a lowerend thereof pivotally mounted on said frame and a connecting memberextending between upper ends of said side members; and

b. a wheel is rotatably mounted on said upper ends of said side membersand has a peripheral rim surface adapted to be in supporting engagementwith said boom.

4. A boom structure as set forth in claim 1 including:

a. spaced elongated legs each having one end thereof pivotally mountedon the other end of said boom support structure and the other endthereof adapted to be in supporting engagement with the ground surfaceat a location spaced from the one end of said frame, said legs eachbeing adjustable in length to thereby support said boom at a selectedspacing above the ground surface and accommodate uneven ground levels;and

b. means mounted on said frame and connected to said legs for retainingsame at a selected spacing from said frame.

5. A boom structure as set forth in claim 1 including:

a. a housing mounted on said frame and having upstanding end portions;

b. a shaft extending between and rotatably mounted on said end portionsof said housing, said shaft having means operatively connected theretofor rotating same;

c. a first sheave and a second sheave each on said shaft, one of saidfirst and second sheave being connected to said shaft, said first sheaveand said second being in spaced relation;

d. means mounted on said first sheave and on said second sheave and onsaid housing for effecting rotation of one of said first and secondsheaves in one direction in response to rotation of the other of saidfirst and second sheaves in the other direction; and

e. a first cable mounted on said first sheave and a second cable mountedon said second sheave and each cable having means thereon adapted to beattached to respective portions of the load whereby one of said firstand second cables is dispensed and the other cable is retracted tothereby control swinging movement of the load relative to said frame.

6. A boom structure as set forth in claim 1 wherein the pivotal mountingof the one end of said boom support structure on said frame includes:

a pair of tubular axle supports each mounted on said frame adjacent arespective one of said opposite sides thereof;

b. an elongated axle member having opposite end portions thereofreceived in respective axle supports and rotatable therein;

0. a pair of tubular end members each mounted on the lower end ofa-respective one of said side frames of said boom support structure andsleeved on said axle member whereby said boom support structure isfreely rotatable on said axle member;

d. means mounted on said axle member and in engagement with each of saidend members of said boom support structure side frames for retainingsaid adjacent said respective axle supports; and

e. means mounted on each of the opposite end portions of said axlemember and positioned outwardly of said axle supports for retaining saidaxle member therein.

7. A boom structure as set forth in claim 1 wherein the pivotal mountingof the one end of said boom on said frame includes:

a. a pair of tubular axle supports each mounted on said frame adjacent arespective one of said opposite sides thereof;

b. an elongated axle member having opposite end portions thereofreceived in respective axle supports and rotatable therein;

c. a tubular end member mounted on the one end of said boom and sleeveon said axle member whereby said boom is freely rotatable on said axlemember;

d. meansmounted on said axle member and in engagement with said endmember of said boom for retaining same against lateral movement of saidtubular end member along said axle member; and

e. means mounted on each of the opposite end portions of said axlemember and positioned outwardly of said axle supports for retaining saidaxle member therein.

8. A boom structure as set forth in claim 1 including:

a. a housing mounted on said frame and having upstanding end portions;

b. a shaft extending between and rotatably mounted on said end portionsof said housing, said shaft having means operatively connected theretofor rotation same;

c. a first sheave secured on said shaft and rotatable therewith;

d. a second sheave rotatably mounted on said shaft and being in spacedrelation with said first sheave, said second sheave being movablelongitudinally along said shaft;

e. means mounted on said first sheave and on said second sheave and onsaid housing for selectively effecting rotation of one of said first andsecond sheaves in one direction in response to rotation of the other ofsaid first and second sheaves in the other direction; and

f. a first cable mounted on said first sheave and a second cable mountedon said second sheave and each cable having means mounted thereonadapted to be attached to respective portions of the load whereby one ofsaid first and second cables is dispensed and the other cable isretracted to thereby control movement of the load.

1. A boom structure comprising: a. an elongated generally horizontalframe having opposite sides and opposite ends, said frame having meansadjacent the opposite ends thereof for supporting said frame relative toa ground surface; b. an elongated boom having an upper surface and alower surface and one end thereof pivotally mounted on said frame, saidone end of said boom being positioned intermediate the ends of saidframe; c. an elongated boom support structure having one end thereofpivotally mounted on said frame adjacent one end thereof and the otherend adapted to be in supporting engagement with the lower surface ofsaid boom, said one end of said boom support structure being spaced fromsaid one end of said boom, said boom support structure having laterallyspaced side frames each positioned on respective opposite sides of saidboom and having a lower end thereof pivotally mounted on the one end ofsaid frame adjacent a respective one of the opposite sides thereof, saidboom support structure having a wheel rotatably mounted between upperends of said frames and having a peripheral rim surface in supportingengagement with the lower surface of said boom; d. an elongated flexiblemember operatively engaging the other end of said boom support structureand means operatively connected to said flexible member for moving saidboom support structure to thereby selectively raise and lower said boom;and e. a second elongated flexible member extending over the other endof said boom and means operatively connected to said second flexiblemember for selectively raising and lowering a load, f. said boom supportmember further having elongated legs each having and end thereofpivotally mounted on the other end of said boom support member and theother end thereof adapted to be in supporting engagement with the groundsurface at a location spaced from the one end of said frame.
 2. A boomstructure as set forth in claim 1 wherein: a. one end of said frame isadapted to be removably connected to a mobile vehicle; b. said frame haslaterally spaced ground engaging wheels mounted adjacent the other endthereof for supporting said frame for movement along the ground surfaceby the mobile vehicle; and c. said legs are each adjustable in length tothereby support said boom at a selected spacing above the ground surfaceand to accomodate uneven ground levels.
 3. A boom structure as set forthin claim 2 wherein: a. said boom support member has spaced side memberseach having a lower end thereof pivotally mounted on said frame and aconnecting member extending between upper ends of said side members; andb. a wheel is rotatably mounted on said upper ends of said side membersand has a peripheral rim surface adapted to be in supporting engagementwith said boom.
 4. A boom structure as set forth in claim 1 including:a. spaced elongated legs each having one end thereof pivotally mountedon the other end of said boom support structure and the other endthereof adapted to be in supporting engagement with the ground surfaceat a location spaced from the one end of said frame, said legs eachbeing adjustable in length to thereby support said boom at a selectedspacing above the ground surface and accommodate uneven ground levels;and b. means mounted on said frame and connected to said legs forretaining same at a selected spacing from said frame.
 5. A boomstructure as set forth in claim 1 including: a. a housing mounted onsaid frame and having upstanding end portions; b. a shaft extendingbetween and rotatably mounted on said end portions of said housing, saidshaft having means operatively connected thereto for rotating same; c. afirst sheave and a second sheave each on said shaft, one of said firstand second sheave being connected to said shaft, said first sheave andsaid second being in spaced relation; d. means mounted on said firstsheave and on said second sheave and on said housing for effectingrotation of one of said first and second sheaves in one direction inresponse to rotation of the other of said first and second sheaves inthe other direction; and e. a first cable mounted on said first sheaveand a second cable mounted on said second sheave and each cable havingmeans thereon adapted to be attached to respective portions of the loadwhereby one of said first and second cables is dispensed and the othercable is retracted to thereby control swinging movement of the loadrelative to said frame.
 6. A boom structure as set forth in claim 1wherein the pivotal mounting of the one end of said boom supportstructure on said frame includes: a pair of tubular axle supports eachmounted on said frame adjacent a respective one of said opposite sidesthereof; b. an elongated axle member having opposite end portionsthereof received in respective axle supports and rotatable therein; c. apair of tubular end members each mounted on the lower end of arespective one of said side frames of said boom support structure andsleeved on said axle member whereby said boom support structure isfreely rotatable on said axle member; d. means mounted on said axlemember and in engagement with each of said end members of said boomsupport structure side frames for retaining said adjacent saidrespective axle supports; and e. means mounted on each of the oppositeend portions of said axle member and positioned outwardly of said axlesupports for retaining said axle member therein.
 7. A boom structure asset forth in claim 1 wherein the pivotal mounting of the one end of saidboom on said frame includes: a. a pair of tubular axle supports eachmounted on said frame adjacent a respective one of said opposite sidesthereof; b. an elongated axle member having opposite end portionsthereof received in respective axle supports and rotatable therein; c. atubular end member mounted on the one end of said boom and sleeve onsaid axle member whereby said boom is freely rotatable on said axlemember; d. means mounted on said axle member and in engagement with saidend member of said boom for retaining same against lateral movement ofsaid tubular end member along said axle member; and e. means mounted oneach of the opposite end portions of said axle member and positionedoutwardly of said axle supports for retaining said axle member therein.8. A boom structure as set forth in claim 1 including: a. a housingmounted on said frame and having upstanding end portions; b. a shaftextending between and rotatably mounted on said end portions of saidhousing, said shaft having means operatively connected thereto forrotation same; c. a first sheave secured on said shaft and rotatabletherewith; d. a second sheave rotatably mounted on said shaft and beingin spaced relation with said first sheave, said second sheave beingmovable longitudinally along said shaft; e. means mounted on said firstsheave and on said second sheave and on said housing for selectivelyeffecting rotation of one of said first and second sheaves in onedirection in response to rotation of the other of said first and secondsheaves in the other direction; and f. a first cable mounted on saidfirst sheave and a second cable mounted on said second sheave and eachcable having means mounted thereon adapted to be attached to respectiveportions of the load whereby one of said first and second cables isdispensed and the other cable is retracted to thereby control movementof the load.